A letter published by The Guardian this week, credited to Guardian Staff, takes up a question many households now ask in front of the milk fridge: how much iodine does cow's milk actually supply, and what changes when some of it is replaced with a plant-based drink? The letter's core point is short. "Cow’s milk is not a natural source of iodine." According to the letter, milk gets its iodine through fortification, which means the nutrient is added on purpose rather than being a built-in feature of the drink. That detail matters for any family planning a switch, because a plant-based alternative is less likely to supply iodine unless its maker has added it.
The letter also refers to a report in which scientists said that moving even partly from dairy products to vegan alternatives could lead to deficiencies in iodine and other micronutrients if the substitutes are not fortified. You can read the original letter here: Clearing up confusion over iodine in milk, a Guardian letter.
Why Iodine Gets Attention at Home
Iodine is a nutrient the body uses to make thyroid hormones, and it is needed in small amounts throughout life. General public health guidance says most people get it from a mix of foods, with dairy, eggs, seafood, and iodized salt among the common sources. Because that mix differs from household to household, a single change in one food can shift the total more than families expect. That is not a reason for worry. It is a reason to look at the labels once, calmly, and to know what is in the cupboard.
A Calm Pantry Check
First, read the label on every plant-based drink in the house. Look for iodine in the nutrition panel or the ingredient list. Many fortified products state it, but not all do. Brands within the same product line can differ, and formulas can vary between markets, so check the carton you actually bought rather than relying on memory.
Second, compare before you swap. If a drink lists iodine, note the amount per serving and how it compares with the milk it would replace. The percentage shown on many panels is a guide to daily intake, not a target to reach with one glass.
Third, write a short family card. List which drinks are fortified, which are not, and which ones the family uses for cereal, cooking, or drinking. Post it near the fridge so anyone shopping or cooking can see it at a glance.
Fourth, check the salt. Many kitchens use iodized salt for everyday cooking. Confirm which type is in the cupboard and whether it is used regularly, since salt is one of the most common iodine sources in the home.
Fifth, handle cartons as the label directs. Shake the carton if the label asks for it, keep opened cartons cold, and use them by the date printed on the pack.
Keep the Balance Steady
Seaweed and some supplements can contain very different amounts of iodine from one product to the next, so the general advice is to treat them as occasional items and check labels instead of adding them by habit. Supplements should not be started or stopped based on a news item or a kitchen check. If a household is considering a larger change in diet, such as cutting dairy for a child, an older relative, or a person with a specific health condition, the right next step is a conversation with a doctor, dietitian, or pharmacist who knows that person's needs.
The aim is steady, ordinary habits. One label read, one card on the fridge, and one check of the salt will tell most families more than any headline. The letter is a useful reminder that a food we rarely think about can still shape what our bodies get each day.